This invention relates to integrated circuit packaging. In particular, it relates to a method for preventing damage to a semiconductor wafer during die singulation.
Microcircuits may be fabricated on a substrate of a semiconductor material (e.g., silicon) which is usually called a wafer. Each wafer generally comprises a rectangular array of identical microcircuits. After fabrication, each microcircuit and the portion of the substrate on which it is formed (called a die or chip) is separated from the rest of the wafer. This process is called singulation and may be achieved by sawing through the wafer using, e.g., a diamond-tipped saw.
Once the microcircuits have been singulated, they may be packaged for use in electronic devices.
During die sawing, the wafer is subjected to mechanical stresses which may cause microscopic micro-cracks to be formed in a resultant die.
Over a period of time, these micro-cracks may cause parts of the die-substrate to disintegrate or flake off and may cause the integrated circuit on the die to be become damaged.